Improvement in methods of distilling oils from coal



Sheet 2.

v2 Sheets l.v HOWARTH.

Oil Still.

Patented Sept. 27, 1859.

N, Prrsns. Phnmuxhngmpher. wnsmngtm-t n. c.

Unirrnn ra'rns Pari-entr rrrcn@ JOHN HOVARTH, OF SALEM, MASSACHUSETTS,

lNlPROl/EEVIENT EN METHODS OF DKSTQLLENG @BLS FROM COAL.

Specification forming part of Letters Patent N0. 25,56%, datedrSeptember 27, 1851-9.

T0 all whom, it may concern;

Be it known that I, JOHN HowARTi-r, of Salem, in the county of Essex and State of Massachusetts, have invented a new and useful method of extracting the volatile products from coal and other substances yielding pyrogenous oils, and I do hereby declare that the following description, taken in connection with the accompanying drawings, hereinafter referred to, forms afull and exact specification of the same, wherein I have set forth the nature and principles of my said improvements, by which my invention may be distinguished from all others of a similar class, together with such parts as I claim and desire 4to have secured to me by Letters Patent.

rlhe figures of the accompanying plate of drawings represent my improvements.

Figure l, Plate l, is a side elevation of an apparatus exemplifying my improved method of extracting the volatile products of coal and other substances yielding pyrogenous oils. Fig. 2, Plate l, is a longitudinal vertical scction. Fig. 3, Plate 2, is a top view of the same. y

In the processes heretofore used for extracting the volatile products from coal and other substances yielding pyrogenous oils it has been found that there is a certain temperature at which vaporization takes place, and which temperature it has been the aim of all such processes to maintain as nearly as possible, as any excess of heat beyond this desired temperature produces gases which cannot be converted into oily vapors, and are therefore lost, and any considerable diminution of heat below the proper point prevents, of course, the attainment of the desired result-viz., the producing of oleaginous vapors, but in the many kinds of apparatus heretofore used the substances from which the oil is to be extracted have been exposed either to heat in a retort, which is a roasting or baking process, or to the direct action of an ignited mass of fuel, or in such a manner as to allow the products of combustion to pass through and minglc with the coal or other substances to be acted upon by the heat, by either of which modes it is impossible, even by the utmost care and skill, to produce and maintain uniformly the exact temperature desired and no other during the entire operation, and consequently the oily vapors cannot -be constantly forming. In all these cases the temperature can be lowered only by diminishing the draft, which of course lessens the volume of heated currents passing through the apparatus, and thereby materially checks the rapidity with which the vapors are formed.

The object of the present invention is to maintain the temperature always and during the whole operation at the Vaporizingpoint and no other, and in such a manner that the volume of heated currents passing through the material to be acted upon shall not at any time be diminished, or the rapidity with which the vapors are formed during the process suffer diminution, as a small volume of the heated currents at the proper temperature cannot, it is evident, produce such a quantity of vapors or so rapidly as a larger volume at the saine temperature. I effect these desiderata by subjecting the material from which the oleaginous vapors are to be formed to a current of heated air of the requisite temperature or to a volume of superheated steam, or to both heated air and superheated steam combined, the currents of air or superheated steam being forced through the material to be acted upon under a slight pressure. By this mode the degree of heat can always be regulated and kept at the most advantageoustemperature-viz., that of vaporization-without being dependent upon the fluctuations to which the various modes of heating for similar purposes have heretofore been subject, and without diminishing the volume of currents passing through the apparatus, the regulating being effected, should the degree of heat become too great, which is the greatest difficulty experienced in all processes for forming oily vapors, simply by admitting cold air or steam from the boiler, to mingle with the other currents being forced through the apparatus, the danger of keeping the temperature too low being but slight, as it is evident that there will be but little difficulty in keeping the air or steam up to the proper degree of heat, as a comparatively small iire is needed for the purpose. It will be seen, also, that by this mode every portion of the material from which the volatile products are to be extracted vis acted upon equally and at the same time by a heated current of the requisite temperature, which cannot be effected where the heat is merely that of conduction by metal or by direct contact of the products of combustion with the material to be acted upon.

a c in the accompanying drawings represent a brick furnace, within which, and at a suitable distance above the gratebars b b, is placed a worm or coil of pipes, c c, through which steam from a boiler or atmospheric air, either separately or in combination, is forced under slight pressure and heated in the furnace a c to the required temperature, and then passes to the cylinder d d, filled with the coal or other sub- 4 stances from which the volatile products are to be extracted.

In the drawings I have showntwo modes in which the heated currents may be conducted through the cylinder d 1 -viz., from the bottom to the top and from the top to the bottom, as may be most desirable. When substances that melt in the retort are used, I prefer to have the heated air or superheated steam p ass into the cylinder at the bottom; but when this is not the case the currents should pass in at the top. The red arrows in Fig. 2 show this latter method, the air or steam passing from the heated coil of pipes c c up thetube e @and :in at the top of the cylinder d d, whence it is forced down through the coal or substance to be acted upon, passing through the perforated plate or diaphragm f, thatI sustains the charge, into a pipe, g, that leads to the condenser hh. The condensed products are delivered at the bent tube \Vhile conducting the heated currents in this manner, it will be evident that the communications at k, Z, andm must be cut off by valves, cocks, or other suitable devices.

rIhe blue arrows in Fig. 2 show the manner of passing the heated currents through the cylinder d d and the coal or other substances therein from the .bottom to the top, the communications at 7s, Z, and m being of course opened, and those at a, o, and p closed, when the heated air or superheated steam passes from the worm c c into the pipe f/ up through the perforated plate f and cylinder d d and its con tents into the pipe r 1*, and then downward into the condenser h h., when the products are drawn off, as before, at the bent tube t'. The superheated steam or air when at too high a temperature can quickly be reduced to the proper degree of heat without diminishing the volu me of the heated current passing through the cylinder d d by admitting steam directly from the boiler through apipe, t, or by allowing cold air to mingle with the heated currentsin any proper lnanner.

u a is an outer cylinder or casing holdinga packing of dry clay or plaster to prevent the escape of heat from the cylinder d el.

rIhe coke after the process is completed can be readily removed, as it is only necessary to hoist the plate f by means of a hook, o, Fig. 2. rIhe cylinder l d is then recharged, and the process goes on as before.

In the manufacture of coal-oil I do not claim the application of superheated steam or heated air, broadly or separately; but

That I claim as new, and desire to secure by Letters Patent, is-

1. Forming oleaginous vapors from coal or other substances yielding pyrogenous oil by passing through the material to be acted upon a current of superheated steam, in combination with steam direct from the boiler, substantially in the manner and for the purposes stantially in the manner and for the purposes set forth.

JOHN HOWARTH.

Witnesses:

J osnrH Gavnrr, ALBERT W. BROWN. 

